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Electronic Circuits in Action
Published in Trevor Linsley, Electronic Servicing and Repairs, 2014
The electricity generating stations generate a sinusoidal alternating voltage waveform from an alternator which is usually driven by a steam turbine. A sinusoidal waveform is arepetitive, analogue waveform; repetitive because in the case of the a.c. mains it repeats itself fifty times each second, and analogue because it varies smoothly and continuously between two extremes. In everyday life, analogue systems are all around us. Television, radio and telephone signals are all analogue, the amplifier considered earlier is an analogue amplifier. A car speedometer and fuel gauge are analogue instruments. Analogue electronics is one oftwo main branches of electronics, the other isdigital electronics. Digital signals do not change smoothly and continuously between voltage levels but have two quite definite levels, either on or off. Digital signals are in the form of electrical pulses whose outputs involve only two levels of voltage, called high or low, where high might be +5 V and low 0 V. The termmark-to-space ratio is used in connection with digital signals, particularly square, rectangular and pulse waveforms, and is given by mark-to-spaceratio=marktimespacetime
Background
Published in Russ Martin, Sound Synthesis and Sampling, 2012
Analogue electronics is concerned with signals: audio, video, instrumentation or control signals. These are usually direct representations of the real-world value, but converted in to an electrical signal by some sort of transducer or converter, analogue signals indicate the value by voltage or current. For example, a device for measuring the level of a liquid in a tank might produce a voltage and by connecting this voltage to a calibrated indicator or meter, the level can be monitored remotely. Being able to connect a meter across an analogue circuit and directly measure a voltage is typical of analogue circuitry, and is rarely possible with digital circuits, which normally require more complex equipment to monitor what is going on.
Effects of the wire mesh on pulsed eddy current detection of corrosion under insulation
Published in Nondestructive Testing and Evaluation, 2023
Zhiyuan Xu, Zhen Zhou, Hanqing Chen, Zhongyi Qu, Jixiong Liu
Figure 15 shows the experimental signals acquired on the L0D0 zone of the plate SP1 by using type 304 stainless steel, aluminium and type Q195 mild steel wire meshes, respectively. It is clear that the result agrees well with the simulation result shown in Figure 6, that is, only the mild steel wire mesh causes decrease to the signal amplitude. The noise level of the experimental signal, measured by putting the probe in the air, is on the order of 10−2 V. When putting the probe onto the cladding, the interference caused by the probe vibration is synchronised with the PEC pulses [21] is mixed in the signal, making the noise level further higher. Another point is that, the experiment system is designed as simple as possible, and additional analogue electronics such as the hardware filter are not involved in reducing the signal distortion.
Wheel flat analogue fault detector verification study under dynamic testing conditions using a scaled bogie test rig
Published in International Journal of Rail Transportation, 2022
Esteban Bernal, Maksym Spiryagin, Colin Cole
Figure 11 shows the Hardware-in-the-Loop (HIL) experimental setup used to verify the WF-AFD functionality with a real accelerometer signal and to establish if the WF-AFD is robust enough to produce a correct diagnosis event when the input signals contain the vibration noise produced by a bogie operating at 60 km/h. The WF-AFD analogue electronics circuit implementation was connected to the PC through a DAQ device. In this way, it was possible to feed the WF-AFD with the healthy and defective wheelset acceleration signals recorder earlier at 5 kS/s on the scaled bogie rig. The DAQ also provided power and both impact threshold and wheel flat threshold signals inputs, at a constant voltage for each test. The fault presence signal produced by the WF-AFD was simultaneously recorded by the DAQ hardware interface device. With this HIL experimental setup, it was possible to verify the correct operation of the WF-AFD because the DAQ hardware interface allows to simulate the same inputs and outputs the device would have when installed in a condition monitoring sensor node in the field, connected to an accelerometer sensor and a digital input of a microcontroller unit.
A novel simple BiCMOS Current Controlled Current Conveyor for RF applications
Published in International Journal of Electronics Letters, 2020
Mohamed A. Yakout, Tareq A. Alawadi
Ever since the 1970s, the next step of current conveyors design, second-generation current conveyors (CCIIs), started to be adapted (Sedra & Smith, 1970). Thus second generation CCIIs have been utilised in many applications throughout the past five decades, particularly in the field of Analogue electronics covering areas such as amplifiers (Tripath et al., 2013), inductance simulators (Salem et al., 2006), filters (Koton et al., 2009) (Ranjan et al., 2014) (Aminzadeh, 2018) (Herencsar et al., 2017) (Zhu et al., 2018), Oscillators (Horng, 2001) (Minhaj, 2007) and signal processing (Senani et al., 2015) to name a few. Also, CCIIs have been adapted for real applications such as controlling the speed of DC motors (Kumari et al., 2018), capacitive touch sensors (Hwang et al., 2018) and radio frequency circuits design (Ettaghzouti et al., 2018) (Brinson & Kuznetsov, 2016). Towards the end of the millennium (Mid 1990s onward) bipolar and by contrast BiCMOS technologies were utilised in realising current controlled conveyors (CCCIIs) (Fabre et al., 1995) (Fabre et al., 1998) in an effort to get the best traits of both bipolar and CMOS technologies.